Moody, intricate and introspective metal isn't necessarily the natural choice for a festival headlining slot, but over the course of their bleak and riveting 90-minute set New Jersey's All Points West Festival Saturday night, Tool proved that sometimes mystery is more compelling than stridency.

On a bill loaded with indie rock, Tool seemed initially distinguished by their popularity. They were the only band on Saturday's bill to have a platinum record, and the only performers to have won Grammys, and the only ones with enough starpower to sell out arenas on their own. And yet despite their high profile, Tool hardly behave like a mainstream band. Saturday's set was an exercise in atmosphere — a dark, riveting performance that minimized the members of band while foregrounding their stranger sensibilities.

Visually, the show was stunning. Tool perform to a series of bleak films mostly created by the artist Adam Jones, and beamed out giant-size across Liberty State Park they seemed more imposing and unnerving than ever. Opening with the sinister, twisting "Jambi," the group slowly worked its way through a set that spanned its small catalog. Part of what makes Tool concerts such visceral experiences is the band's peerless sense of control and release. Songs start with icicle drip guitars and rolling, tribal percussion, steadily building to perfectly timed explosions of sound. When paired with Jones' frightening films, it became more like a theater experience than a concert. At times it was remarkably easy to forget there was a band onstage at all.

Which, in a way, seemed like part of the intention. Frontman Maynard James Keenan remained near the back of the stage for much of the set. Positioned up near the drum riser, he contorted his rail-thin body into a series of strange, unsettling positions. He was more shadow than flesh, and his spindly silhouette seemed downright demonic, twisting and twitching in front of the digital images. He's an odd, willfully enigmatic frontman — at once sinister and threatening — and his strained croon gave Tool's songs a sense of both agony and urgency. It seemed baffling that Tool's fans reacted with such hostility to My Bloody Valentine, because in a way, the two bands have fundamental similarities. Both deliver willfully detached, remote performances, maximizing on bludgeoning volume and masking raw sentiments in razor-sharp sheets of sound.

Whether visually or lyrically, Tool seem obsessed with the notion of human grotesques. The film played during "Stinkfist" depicted aqua-colored men inhabiting an odd, grimy sub-basement, existing either in a state of perpetual shunning or punishment. During "Schism," a zombielike man worked his way through a cramped hallway, seeming driven not so much by a need for escape as by simply the need to move. The protagonists in Tool songs are perpetually unfit to occupy the same space as the rest of us, and so they're either locked down or chained up for their own good, or to spare us the awkwardness of having to deal with them.

In a larger sense, all of this serves as an elaborate metaphor for emotional isolation — hardly the bread-and-butter of a festival set — but Tool's knack for coiled tension somehow made the whole thing work. Near the end of the night they brought out session drummer Frank Ferrer — hardly anyone's idea of a "surprise guest" — to provide auxiliary percussion on "Lateralus." Ferrer has no bona fides to speak of, but his playing was fluid and potent — a fitting ending to a performance where the musicians seemed to be the least important element.